I have a main activity, that when I click on a button, starts a new activity, i used the following code to do so:
Intent intent = new Intent(this, SettingsAc
I think you are calling finish() method in MainActivity before starting SettingsActivity.
The scenario which you have described will occur in following two ways:
EITHER
You have set android:noHistory = "true" for MainActivity inside AndroidManifest.xml which causes MainActivity to finish automatically on pressing the back key.
OR
Before switching to your 'SettingsActivity', you have called finish() in your MainActivity, which kills it. When you press back button,since no other activity is preset in stack to pop, it goes back to main screen.